2014 Zhejiang Provincial Competition

ZOJ 3777 Problem Arrangement

State compression DP, seed dp,dp[s][m] represents the number of scenarios in which the current occupied position has a set score of M, the parent is the total n!, the memory search is good to write

by FD

ZOJ 3785?

Geometric series, inverse yuan, fast power, of course, can be violent to find the circulation section, there is a mod must have a cycle section, because x^y%7 equivalent to (x%7) ^y, so can be divided into 6 series, as follows

1^1,2^2,3^3,4^4,5^5,6^6,0^7

1^8,2^9,3^10,4^11,5^12,6^13,0,^14

...

Each column is geometric series and then summed with geometric series a1* (q^n-1)/(q-1) = = a1* (q^n-1) *INV (q-1)

by FD

2014 Zhejiang Provincial Competition